The present invention relates to slide frame assemblies for receiving chemical analysis films. More particularly, the invention relates to the structure of a slide frame assembly into which a chemical analysis film for analyzing the components of a liquid sample in an optical density measurement is inserted. The invention further relates to the structure of a chemical analysis slide which is prepared by inserting a chemical analysis film in such a slide frame assembly.
Chemical analysis films or sheets for aqueous solution samples (hereinafter referred to as "chemical analysis films" when applicable), and especially new multi-layer type chemical analysis film used for quickly analyzing a component or components in a body fluid such as blood or urine, are generally well known in the art. Films or sheets of the general type to which the invention pertains are disclosed, for example, in U.S. Pat. Nos. 3,992,158, 3,983,005, 4,042,335 and 4,066,403, and Published Unexamined Japanese patent application No. 164,356/80 (corresponding to U.S. co-pending application Ser. No. 157,737 filed on June 9, 1980).
The structure of such a conventional chemical analysis film 40 is such that, as shown in FIG. 1, a single or plural reagent layers 44 can be placed on a transparent support 42 and a porous spread layer 46 placed on the single or plural reagent layers 44. Then, these layers are formed into a single unit so that they may not be peeled apart. Alternatively, only the porous spreading layer 46 and the single or plural reagent layers 44 form the chemical analysis film 40.
A liquid sample dropped onto the porous spreading layer of of chemical analysis film spreads uniformly through the porous spread layer 46 and enters the reagent layer for chemical reaction as a result of which the sample is colored or its color is changed. The degree of this change in color can be determined by observing or measuring the optical density through the reagent layer or the transparent support.
In this determination, a component in the liquid sample reacts with the reagent in the reagent layer. In this reaction, the coloring reaction of an organic reagent in water is often utilized. The chemical analysis film has a significant feature that the analyzing operation is of the dry type. The chemical analysis film is supplied after being inserted into a cartridge such as that disclosed in Japanese Laid-Open Utility Model Application No. 162294/1979 or into a slide frame which is similar to a conventional slide frame for a transparent positive picture photographic film. For quantitative analysis, the optical density of the chemical analysis slide in which the chemical analysis film has been inserted is measured by a chemical analyzer as disclosed in U.S. Pat. Nos. 4,119,381 and 4,152,390 and in U.S. co-pending application Ser. No. 212,009 filed on Dec. 1, 1980 so that the component to be detected is subjected to quantitative analysis.
These conventional slide frames are specifically intended as slide frames for transparent positive picture films which have been used for slide frames for receiving chemical analysis films. The conventional slide frames are not always sufficient for the strict or accurate measurement of optical density values. More specifically, the conventional slide frames are disadvantageous in the following points. First, usually the slide frame is white or light grey or light-colored and the surface of the slide frame is glossy or semi-glossy. Therefore, when a light beam is applied to the slide frame for an optical density measurement, rays scattered from the light beam and rays scattered and reflected from the chemical analysis film, reflected from the surface of the slide frame and from the side walls of the opening in the slide frame, enter the photometric path or the photometric unit in the chemical analyzer and cause errors in the measurement of optical density. In addition, the configuration and size of the opening in the slide frame are not always suitable for the measurement of optical density.
Accordingly, an object of the invention is to provide a slide frame assembly for a chemical analysis film with which an optical density measurement of high accuracy can be achieved using an optical reflection method or an optical transmission method.
Another object of the invention is to provide a slide frame assembly for a chemical analysis slide, the surface of which does not scatter or reflect rays scattered from a light beam for optical density measurement or rays scattered and reflected from the chemical analysis film.
A further object of the invention is to provide a slide frame assembly for a chemical analysis slide which has the end face of an opening formed therein which does not scatter or reflect rays scattered from a light beam for optical density measurement or rays scattered and reflected from the chemical analysis film.
A still further object of the invention is to provide a slide frame assembly for a chemical analysis slide in which the surface on which a liquid sample is dropped or stuck can be readily discriminated.